How do you make your shield for embedded systems & RF?

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Hi everybody
i have a question about the shield for embedded systems & RF:
how do you make your shield for embedded systems & RF?
actually, do you make your shield or buy? :roll:
any article or page or... for guide to make a shield?(for anti-noise and protect)





"One's value is inherent; money is not inherent"

 

Chuck, you are in my heart!

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For prototypes I have used bismuth tape.

It all starts with a mental vision.

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I generally only use shields in a very few cases.

One is when I have an RF transceiver on the same board and a harmonic of the crystal falls into one of the frequencies to be received. Another is if I have an oscillator that needs to be very stable and I want to keep out all the digital noise from nearby circuits.

Otherwise, I don't use them unless it is the only way to pass FCC/CC emissions test. But, usually when that happens, the nasty stuff comes from I/O lines, power, and such. Then, shields don't do much.

Jim

 

Until Black Lives Matter, we do not have "All Lives Matter"!

 

 

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I found them at digikey. Haven't used any yet. On Jim's recommendation, I'll not waste my effort. IO and power lines: Pay attention to IO and power lines.

If you don't know my whole story, keep your mouth shut.

If you know my whole story, you're an accomplice. Keep your mouth shut. 

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I agree with Jim, there are often better solutions.

I designed a shield for 14 bit analog measurement system that was pressed up against a 600 VAC input voltage SMPS.
Power supply placement was dictated by non-engineer managers. The A/D was used to measure noise, and various shields fabricated and tested. I found increasing shield area, after a point made noise worse, by collecting and radiating. Moving the supply a few inches was a better solution, it reduced coupling to adjacent current transformers, but managers held their ground. Sorry for sharing too much. The situation did not bring happy thoughts.

It all starts with a mental vision.

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One of them had pointy hair?

If you don't know my whole story, keep your mouth shut.

If you know my whole story, you're an accomplice. Keep your mouth shut. 

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All hairs are pointy.

This calls for bold engineers.

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Torby wrote:
One of them had pointy hair?

No, he was their boss, but too important to go to meetings. And I was not invited.

I do not know the end of the story, I found the door, and made fame elsewhere :).

It all starts with a mental vision.

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I think I worked for him. We had a nickname for him. (I can not type it out though.......)

:)

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Depends the volume, the mechanical eng. helps on this kind of stuffs. And after we send to some mechanical manufactures.
Similar of metal cases..

Regards,

Bruno Muswieck

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@KitCarlson
Thank you Kit for reply,
i'm eager to see a sample of your job.
@Jim
Thank you Jim for reply
can i see a sample of your job?(picture for FCC/CC emissions and I/O lines, power)
@All guys
Thank you for reply

"One's value is inherent; money is not inherent"

 

Chuck, you are in my heart!

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It is not proper to share that type of picture information, it is considered confidential by employer.

Shielding is specialized. It helps to have a good understanding of electromagnetic field theory. With that, trial and error, along with imperial evidence, helps in the design. A shield is never a perfect solution.

It all starts with a mental vision.

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WoOoW!
anyway, thank you, kit.

"One's value is inherent; money is not inherent"

 

Chuck, you are in my heart!

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KitCarlson wrote:

Shielding is specialized. It helps to have a good understanding of electromagnetic field theory. With that, trial and error, along with imperial evidence, helps in the design. A shield is never a perfect solution.

Kind of, calculate your wavelenght for the size of your holes or make it without.

Regards,

Bruno Muswieck

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I can only guess, best to try and see how that works.

It all starts with a mental vision.

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Quote:
any article or page or... for guide to make a shield?(for anti-noise and protect)

A very good reading by John R. Barnes:
Electronic System Design: Interference and Noise Control Techniques. Contains almost all the topics.
Happened to have hard copy translation.

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http://www.tecan.co.uk/rfiemi/pr...

I've used this when prototyping femtocells.